Ain is a slender, curvaceous young woman with reddish-brown eyes and dark blue hair framing her face, which is held back with a hairpiece in the same upside-down Marine symbol that Z uses. Like Z, she wears a black and gold captain's coat, while underneath her clothes appear quite formal due to her high heels, black leggings, and brown top and skirt. She also wears a large white bow on the front of her collar. When she was a marine, she wore a sleeveless shirt with a tie. Her second (main) battle outfit consists of a blue hooded cape (the Neo Marine jolly roger on the back), a sleeveless white-collar purple top that exposes her navel, grey mini shorts that exposes her long legs, black high heels, and a holster on her right leg.
Most noticeably, Ain has a large "X"-shaped scar on her right leg, possibly received when she was attacked and heavily wounded during a training mission that resulted in the deaths of all the young Marines under Z's command save herself and Binz.
She is rather strict and serious at all times. She rarely shows emotions though she was concerned about her mentor when he was in danger, and she was seen crying when Z was killed by the Marines. Like the rest of the Neo Marines, she fully supports Z's plans despite the risks.
She is very strict with her subordinates and would punish her subordinates if they fail to accomplish a task. Despite this, she would take the blame of her subordinates' failure, such as when she apologized to Z for the defeat of Shuzo, saying she should have made the consequences of failing clearer to him.
She greatly respects Z, having been trained by him and having served under him while still in the Marines, as she refers to him as "Z-Sensei". Her respect is so much so that she defected from the Marines to join his cause, which led them to become criminals in the eyes of the World Government. She is very fond of him, showing concern whenever Z is involved. When Z choose to stay back to buy time for the Neo Marines and the Straw Hat Pirates to escape, she attempted to aid him but Kuzan created a wall of ice, blocking her from helping Z. When Z died, she paid her respects to him, and despite showing little to no emotions previously, she didn't hesitate to cry about it.
Abilities and Powers
Having been personally trained by Z, Ain is an extremely powerful fighter. The fact that she is the second-in-command of the Neo Marines, an organization powerful enough to defeat many New World Pirates, is a testament of her strength. She is capable enough to fight Shuzo in combat for five hours straight and ultimately win with tactics, and to fight against Roronoa Zoro. Alongside Binz, Ain was the only one to survive an attack by an immensely powerful pirate who slaughtered all of Z's students during a training mission.
Ain has extraordinary superhuman physical prowess. She has tremendous agility, speed, and reflexes. She easily evades assaults from large numbers of Marines at once and attacks just as quickly. She is exceptionally strong as the force of her dagger strikes can cut down numerous Marines at once with great ease. She has excellent stamina, able to fight Shuzo for five hours, and ultimately defeat him.
Ain is extremely skilled in dual-wielding her daggers in a reverse grip. She single-handedly cut down large numbers of well trained Marines with great dexterity and precision. She is capable of holding her own against Zoro, an extremely powerful master swordsman.
Ain is highly intelligent. She could use effective strategies to gain a great advantage over her enemies. In her fight against Shuzo, Ain relies on sheer wits to subjugate the former Vice-Admiral of the Marines. During the attack on the Thousand Sunny, Ain used her fighting skills in conjunction with her Devil Fruit abilities to defeat Chopper, Nami, Brook, and Robin who are extremely capable fighters, showing great tactical versatility. She managed to hold her own against Zoro for an extended period of time by exploiting the terrain which she shifts back into lava using her powers.
- Further information: Modo Modo no Mi
By using her power on someone, their body becomes younger, allowing her to weaken them by reverting them to a point before they achieved their current level of strength, such as when they were children. If she uses her power on someone enough times, then she can de-age them to a point before they were born, causing them to disappear forever.
She can also use her power on objects and the terrain, allowing her to take away her targets footing. She can trap victims in the grounds by reverting it to the way it was before an empty space had been worn or broken into it, causing the earth to re-tighten around her opponent. She can also attack her opponent by using her power on hardened lava, allowing her to revert it back to the molten state.
At the beginning of the movie, Ain is seen wielding two short swords shaped like daggers when fighting the Marines. During her fight against Roronoa Zoro, she uses those two blades for close-range attacks and two large-barreled guns for long-range ones. She also used one of the latter at close range to threaten Shuzo when he was trapped in the earth.
After the said pirate was promoted to the ranks of Shichibukai, it caused Z to leave the Marines out of indignation; and in loyalty, Ain resigned her position as a Marine officer, alongside Z, Binz, and Shuzo. All of them would become the founding members of the Neo Marines. She eventually fought against Shuzo for the position of second-in-command, and after a five-hour battle, when she was on the verge of losing, she strategically trapped Shuzo in the ground and threatened him with a pistol, winning the position.
Z's Ambition Arc
Ain was commanding the Neo Marines and she was standing alongside Binz waiting for Shuzo to arrive. However, when he did not, she called him. Shuzo wanted to kill Lily's father. and Ain said that if he failed then he would suffer the consequences.
One Piece Film: Z
Ain was first seen on Firs Island, invading it to help secure the Dyna Stones with Z and the Neo Marines. She attacked the Marines on the island and helped Z to retrieve the Dyna Stones. When Borsalino arrived, she quickly gathers the lower Neo Marines back into the ship. After Z blew up the island, Ain was seen worrying about his fate.
Ain was later seen finding Z on the Thousand Sunny, using the help of the Vivre Card. She boarded the ship, and fought some members of the Straw Hat Pirates. She easily subdued Chopper and Nami by turning them into children, and also managed to rejuvenate Robin and Brook. After Z defeated Luffy, Zoro, and Sanji, Ain returned back to their ship with Z, and was surprised when the Thousand Sunny flew away using a Coup de Burst.
Sometime after their fight with the Straw Hat Pirates, the Neo Marines reached Secon Island. Shortly after the Dyna Stones Z planted near the island's volcano exploded, Ain was seen alongside her leader as he was talking about the Grande Imbuto. They were then attacked by Luffy, Zoro, Sanji, and Usopp, who came to get Ain to return the rejuvenated Straw Hats to their normal ages. On Z's orders, Ain fought Zoro briefly, but soon interrupted the fight to evacuate the island. She was later seen aboard their ship, overlooking the island's destruction.
Ain was next seen on Piriodo, listening to the conversation between Kuzan and Z. Sometime later, the Straw Hat Pirates arrived, and she fought Roronoa Zoro one last time. She tried to keep her distances as much as she could and win by injuring him with lava rather than brute force, but Zoro proved to be too strong anyway and managed to win easily. With Ain's defeat, Nami, Robin, Chopper, and Brook returned to their normal ages. She later woke up, and showed up after Luffy has defeated Z. When Borsalino showed up with a troop of Marines and threatened to kill both the Neo Marines and Straw Hat Pirates, Z stayed back to hold them off. Ain tried to run after him, but Kuzan created a wall of ice, preventing her from getting any further. She broke down in tears, knowing that Z was surely going to meet his end. She was last seen alongside Binz, mourning over Z's grave, as Kuzan tried to console them by telling them how great a man Z was.
- Ain, Z, Binz, and a Marine platoon vs. a future Shichibukai
- Ain vs. Shuzo
- Ain vs. Nami and Tony Tony Chopper
- Ain vs. Roronoa Zoro (on Secon Island)
- Ain vs. Roronoa Zoro (on Piriodo)
- Even though Ain's rank is vice-admiral of the Neo Marines, her rank is not mentioned in Japanese (中将, Chūjo) as usually is among the ranks of the Marines, but in English (バイスアドミラル, Baisu Adomiraru) instead. This might be in order to make a distinction between the Marines and the Neo Marines, as their ideals and purposes are different.
- Even though she is a non-canon character, she was placed 45th in the sixth character popularity poll.
- One Piece Manga — Vol. 70 Chapter 691, Ain appears on the chapter cover alongside many Marines in their rookie years.
- One Piece Anime — Episode 575, Shuzo proclaiming he would make a better second-in-command than Ain.
- One Piece Anime — Episode 577, Ain managed to defeat Shuzo to become Z's second-in-command.
- One Piece Movie — One Piece Film: Z, Ain is shown to wear the Marine officers coat.
- One Piece Volume 1000 "Z", Ain's height is revealed to be almost the same as Luffy's.
- One Piece Movie — One Piece Film: Z, Ain displays weapons in One Piece Film Z.
- One Piece Anime — Episode 577, Z and the Neo Marines arrive at Firs Island.
- One Piece Movie — One Piece Film: Z, Ain appears in Movie 12.